Whirlpool separator device

ABSTRACT

A whirlpool separator is described in which a charge of fluid is circulated at approximately 20 to 30 revolutions per minute in a container. Foreign matter having a specific gravity greater than one is thrown by centrifugal force to the periphery of the container. These heavier particles fall to the lowermost portion of the container for eventual discharge. Foreign oily material having a specific gravity less than one is forced to the top of the fluid and into the vortex created by the circulating fluid where it is removed by hydrophobic material located near the vortex. Small fines are removed by filtration.

Unite .3;? States Patent [191 Rod [ Mar. 19, 1974 WHIRLPOOL SEPARATORDEVICE [75] Inventor: Robert 1... Rod, Pacific Palisades,

Calif.

22 Filed: Feb. 10, 1972 21 Appl. No.: 225,268

[52] US. Cl 210/304, 210/313, 210/315,

2,983,384 5/1961 Winslow 210/304 X Primary Examiner-Samih N. ZaharnaAssistant Examiner-F. F. Calvetti Attorney, Agent, or Firm-Miketta,Glenny. Poms &

Smith 5 7 ABSTRACT A whirlpool separator is described in which a chargeof fluid is circulated at approximately 20 to 30 revolutions per minutein a container. Foreign matter having a specific gravity greater thanone is thrown by centrifugal force to the periphery of the container.These heavier particles fall to the lowermost portion of the containerfor eventual discharge. Foreign oily material having a specific gravityless than one is forced to the top of the fluid and into the vortexcreated by the circulating fluid where it is removed by hydrophobicmaterial located near the vortex. Small fines are removed by filtration.

4 Claims, 4 Drawing Figures PATENIEDIMR 1 91914 SHEEI 2 0F 2 TORESERVOIR 42 WHIRLPOOL SEPATOR DEVICE This invention relates generallyto a fluid separator and more particularly to a whirlpool separator forremoving foreign materials having a wide range of specific gravitiesfrom a fluid.

Generally, foreign suspended materials may be removed from a fluid by afiltering process, which discriminates based upon size. An analysis willshow that foreign materials located in a fluid usually consist ofmaterials having a specific gravity greater than the fluid and materialshaving a specific gravity that is less than the fluid. Those materialshaving a higher specific gravity approach a solid condition and if theparticles sizes are large enough, they tend to settle out. Those foreignmaterials having a specific gravity that is less than the fluid areusually lighter than fluid and tend to float on the surface of the fluidbeing cleaned.

In the art of purifying water, most foreign material can be firstremoved by either a separation process or a plurality of separationprocesses, depending upon the size and kinds of foreign material. Theefficiency of the separating process insofar as suspended solids areconcerned is determined as a function of the particles, measured interms of their specific gravity, that remain in the fluid after theseparating process.

The ultimate use of the fluid will determine the degree of purity andclarity required since it is well known that irrigation water anddrinking water have different purity requirements, and hence requiredifferent degrees of separation and filtering.

The present invention is concerned with a combined separator andfiltering system for use with a grey water recirculating system.

In the absence of a community sewer system, dwellings have includedprivate sewage disposal facilities such as cesspools and septic tanks,which accumulate wastes and permit the fluid components thereof todischarge into the earth through a drainage field while the solidcomponents are held and decomposed by natural means. Other sewagedisposal facilities are no more sophisticated than a direct pipe into anearby body of water with no attempt made at the treatment of thesewage.

A major consideration in dealing with preservation of natural resources,is the exploitation of the water resources in connection with humanhabitation. Vast quantities of water are consumed in a typicalhousehold, only a fraction of which is utilized for drinking or cooking.

Most of the water utilized is employed for laundry purposes, washing,baths or showers and in the disposal of human waste. Great quantities ofwater are also utilized for other domestic tasks such as watering lawnsor gardens, washing cars and the like.

In dealing with the problem of water waste management, two categorieshave been established. A first, known as grey water includes the majorportion of water utilized in human activities. The grey water includesall of the water currently being discharged into sewer systems,excepting only the toilet waste products. The output of the toilet isconsidered black Water and include the human wastes which must beultimately disposed. The black water output includes large quantities ofwater, which have been required in toilets to dispose of a relativelysmall quantities of human waste. In most sewage systems, the grey waterand black water effluents are indiscriminately mixed and are ultimatelyapplied to the same waste treatment facility. Since water is rapidlybecoming a resource in short supply, it has been suggested that at leastthe grey water component of the waste output be reclaimed for allpurposes save drinking or cooking.

In order to provide a substantially sewerless community or a sewerlesshouse, it has been discovered that a combination of a grey waterrecovery system and a novel black water waste incinerator can beefficiently utilized. However, because of the quantities of energyrequired to incinerate the water components of any black water system,it has been determined that some means should be provided to concentratethe human wastes.

One such system has been described and claimed in a copending patentapplication entitled Sewerless Disposal System by George C. Roberts andassigned to the same common assignee as the present invention.Recirculating toilet systems are suggested to limit the amount of waterrequired in the disposal of human wastes, concentrating the wastecomponents of black water waste systems have been described in thepatents to .I. W. Dietz, et al., U.S. Pat. No. 3,067,433; R. F. Corliss,U.S. Pat. No. 3,079,612; N. J. Palmer, U.S. Pat. No. 3,473,171 and U.S.Pat. No. 3,537,590. Such recirculating toilet systems reduce the demandfor water in their operation and effectively concentrate the wasteproducts for more convenient disposal.

In recent years, such recirculating toilet systems have achieved greatsuccess and popularity in vehicles such as boats, aircraft, campers andtrailers. These recirculating toilet systems operate on a basic chargeof 3 gallons of liquid and permit approximately to utilizations on asingle charge. If one or more of these recirculating toilet systems wereemployed in a household, the units would require emptying and refillingapproximately twice per month.

According to the present invention, there is disclosed a water purifierfor use with a sewerless house or sewerless community in which greywaste water is separately collected and applied to the water purifierwhere foreign materials are removed and the clear effluent can beaccumulated for further uses.

In the preferred embodiment, the separator consists of a cylindricalholding tank having an upper portion and a lower portion located along acentral vertical axis. The lower portion of the tank has a frustoconical section for holding a charge of fluid and which terminates in awaste collection orifice in the bottommost portion. The fluid in thetank is forced to rotate at a rotational velocity of approximately 20 to30 revolutions per minute. This rotational velocity of the fluid createsa vortex at the centermost portion and an increase in the outer level ofthe fluid.

The rotation of the liquid forces foreign materials having a specificgravity greater than water or one to be centrifugally forced to theperiphery of the holding tank. The separated heavier material willeventually settle from the lower portion to the conical section andthence to the waste collection orifice located at the bottommostportion.

That foreign material having a specific gravity less than one is forcedup into the vortex and into the upper portion of the separator due tothe rotating fluid. A hydrophobic material located in the upper portionof the tank and along the axial center will absorb and adsorb oilyforeign material having a low specific gravity that is located in thevortex of the rotating liquid. The clear effluent is removed from thetank by means of a centrally located pipe that extends into the lowerportion.

Associated with the separator is a dual and 0.5 micron filter thatremoves foreign material having a specific gravity above one. The filterassembly comprises a centrally located output pipe having a plurality ofopenings located on the periphery of said pipe. A twostage filter islocated radially on the pipe and covers the plurality of openings.

A radially oversized solid outer housing completely covers the filterson the periphery and on the upper and lower edge portions. Due to thehousing being oversized, there is an annular groove between theperiphery of the filter and the internal diameter of the housing. Aplurality of openings is located on the lowermost edge portion of thathousing that communicates with the annular groove in said housingthereby providing a suitable passageway for fluid from the lowermosthousing, through the internal periphery of said housing to therebycommunicate with the filters for eventual discharge through the outputpipe.

The separator is sealed and the charge of fluid is limited to thelowermost portion of the tank. The centrally located filter is notnormally immersed in the liquid but rather is located above the definedlevel of the fluid, with only the openings in the lower edge portionlocated in the fluid.

Rotation of the fluid is achieved in the preferred embodiment byinserting fluid under pressure into the lowermost portion of the tank atan angle relative to the cylindrical holding tank thereby imparting arotational velocity to the fluid located in the lower housing. Insertionof the fluid will increase the fluid pressure while rotation of thefluid will cause the outer level of the vortex to rise. The overalleffect is that foreign oily materials with low specific gravity areforced to the uppermost portion of the cylinder to be removed by thehydrophobic material. The large foreign suspended materials having aspecific gravity greater than one are thrown to the sides of the lowerhousing by the centrifugal force of the rotation fluid for eventualdischarge into the discharge orifice located at the bottom of theconical housing. Smaller remaining foreign suspended materials areremoved by the dual 5, 0.5 micron filters.

The clarified fluid is drawn from the holes located in the lowermostedge portion of the filter assembly in the liquid level. The fluid willbe forced into the holes and into the annular groove, through thefilters and into the holes on the output pipe for discharge through thecentrally located pipe.

In the preferred embodiment a cylinder of dry chlorine source fordisinfecting the effluent may be located either inside the output pipeor on that periphery of the output pipe near the hydrophobic material'The size of the chlorine cylinder will be a function of the capacity ofthe unit. The chlorine in either is located so that it will only bewetted when the unit is in operation, hence making it a true demandsystem.

The features which are believed to be characteristic of the inventionwill be better understood from the following description considered inconnection with the accompanying drawings. Further objects andadvantages of the invention will be made more apparent by now referringto the accompanying drawings wherein:

FIG. 1 is a block diagram of a waste management system illustrating thepresent invention in a grey water system;

FIG. 2 illustrates a freestanding separator constructed according to theteachings of the present invention;

FIG. 3 is a plan view of the separator of FIG. 2 illustrating apreferred manifold for creating the whirlpool effect; and

FIG. 4 illustrates a two-stage filter for use with the separator of FIG.2.

Referring now to FIG. 1, there is shown, in an extremely idealizedfashion, an embodiment of a sewerless waste management system adaptedfor use with a single family dwelling 10 having a plurality ofrecirculating toilet systems. It will be recognized, of course, that thesystem illustrated in connection with FIG. 1 could be connected to anyform of shelter having a waste disposal problem. It is assumed, however,that the structure has access to running water.

As seen in FIG. 1, a common waste line 12 is connected to receive greywater effluent from a plurality of lavatory sinks 14, a bathtub 16 whichmay include a shower, a kitchen sink 18 and a washing machine 20. Forthe purposes of the present invention, the black water discharge fromthe toilets are not connected to the common waste line 12.

The black water system is comprised of a plurality of recirculatingtoilet systems 24. Any of the recirculating toilet systems sold byMonogram Industries, Inc. under the trademark Monomatic and as shown inthe patents either to Palmer, Carlson or the other mentioned earliercould be utilized. Each of the recirculating toilet systems 24 isadapted to be connected to a black-water waste drain 26.

When using more than one toilet system 24, the waste drains 26 areconnected to a multi-positional valve 27 which selectively dischargesthe output of each toilet system into a macerator grinder pump 28. Thevalve 27 may be manually or automatically controlled, depending onexternal considerations. A macerator grinder pump 28 such as iscurrently available from Monogram Industries under the trademarkMonopump, is connected to receive the individual contents of therecirculating toilet system 24 at such times as the system is drained bythe action of the valve 27.

The output of the macerator grinder pump 28 is applied to a wasteincineration system 30 of the type described and shown in U.S. Pat. No.3,380,673 or in the copending application of George C. Roberts andDonald A. Dotson, Ser. No. 202,234, filed Nov. 26, I971. The maceratorgrinder pump converts the stored waste products and liquid into a finelydivided slurry which is capable of being pumped to an appropriatedisposal or receptacle. The waste incinerator system 30 is connected toa source of fuel 32 and includes an exhaust stack 34 which returns theCO and water vapor generated through the incineration of wastes, to theatmosphere.

The main waste line 12 preferably includes a sump pump 36 connected to agrey water purification system 38 which provides a first output oftreated water of tertiary quality through a water line 40. The treatedwater can be stored in a reservoir 42 for subsequent utilization forpurposes such as irrigation, watering animals,

or the like. Such water may also be returned to ponds, lakes or streamsor otherwise disposed of without polluting the environment.

A second output from the water purification system 38 is from a wastecollection and storage area 43 which is preferably fed through a line494 to the waste incinerator 30. Solid, non-burnable waste may beremoved directly at the container 43 associated with the waterpurification system 38. Burnable waste, however, may require a maceratorgrinder pump similar to pump 28.

In operation, the accumulated contents of the recirculating toiletsystems 2 are periodically drained by valve 27 and with the aid of themacerator pump 28, the sludge is pumped into the incinerator 30 which isthus charged for operation. The incinerator, when operated, completelyincinerates the comminuted slurry output of the macerator grinder 28,converting the liquid slurry to water vapor, CO and ash, without odor orsmoke. The remaining water utilization elements of the dwelling 10,including the bath l6, lavatory sink 14, the kitchen sink 118 and thewashing machine 20, as they are used, will apply their grey water wasteto the waste line 12 and the sump pump 36, which may or may not have anaccumulating tank, depending upon the needs and use of the system.

Referring now to FIG. 2, there is shown a preferred embodiment of thewater purification system 38, comprising a free-standing cylindricaltank 50 supported by a plurality of legs 51. The cylindrical tank 56 iscom posed of an upper portion 52 and a lower portion 53. A removablecover 54 is sealed to the upper portion 52.

The lower portion 53 of the tank 58 is connected to a frusto conicalsection 55 that terminates in a discharge orifice 56. The dischargeorifice 56 is controlled by means of a valve 57 which controls thedischarge of the solid waste material into a container 58. The container58 is similar to the container 43 illustrated in FIG. 1, and may have aseparate line connected directly to the waste incinerator or simplyaccumulate the solid waste for disposal at a later time.

The input to the tank 50 is achieved through a manifold 60 communicatingwith the interior of the tank by means of a plurality of inlet ports 62.In the preferred embodiment the manifold 60 is located around theoutside periphery of the lower portion 53 of the tank 50 and has 3 portscommunicating with the interior of the tank 50. The three ports arelocated at an angle relative to the tank 50 and are arranged tointroduce the intake fluid from the sump pump 36 (shown in FIG. 1) intothe interior of the tank 50 so as to increase the internal pressure ofthe tank and also cause the fluid located within the tank to have aninitial velocity of approximately 20 to 30 revolutions per minute.

Referring now to FIG. 3, there is illustrated the manifold 60 havingthree ports 62 communicating with the interior of the tank 50. The sumppump 36 communicates the grey fluid from the house dwelling to themanifold 60 for distribution to the three intake ports 62.

Referring now to FIG. 4, there is shown a filter assembly 66 attached tothe cover 54 by an output pipe 70. The output pipe 70 is centrallylocated and is attached at one end to the cover 54 and, the other end,to the filter assembly 66 and is the main structural element forsupporting the filter elements to be described. The pipe 78 is locatedon the axial center of the tank 50 and contains a plurality of holes 72located on the periphery of the pipe.

Located on the upper portion of the pipe 78 and abutting against theinside surface of the cover 54 is a hydrophobic material 74 shaped as acylinder and generally constructed from pressed newspaper or cellulosematerial. The hydrophobic material 74 functions as an oil absorber oradsorber to thereby remove foreign oily material in the fluid having aspecific gravity that is less than one, such as cooking oils and thelike.

The hydrophobic material 74 is supported and rests on a substantiallysolid upper baffle plate 76. The pipe passes through a centrally locatedhole in the upper baffle plate 76 and is fixedly attached at thelowermost portion to a lower baffle plate 78 by a locknut 79. A solidouter housing 80 is connected to the peripheral portions of the upperbaffle plate 76 and the lower baffle plate 78 to thereby completelyenclose and protect the interior portion from contact with the externalfluids.

Located within the solid outer housing 80 and between the upper baffle76 and the lower baffle 78 are a pair of cylindrically shaped two-phasefilters 82 and 84. The inner filter 82 is a fine" filter for removingforeign material having a particle size greater than approximately /2micron. The outer or coarse" filter 84 will filter all other foreignmaterial having a particle size greater than approximately 5 microns.

The filters 82 and 84 are commercially available and are generallyconstructed of pleated paper. The external diameter of the coarse filter843 is chosen to be less than the internal diameter of the solid outerhousing 80 to thereby define an annular passageway 86, extending.

lengthwise from the lower baffle plate 78 to the upper baffle plate 76.

The lower baffle plate 78 is substantially solid, except for a pluralityof holes 88 located on the periphery" thereof which communicates with acentral opening 90 also located within the lower baffle plate 78. Asubstantially radial passageway 92 in the lower baffle plate 78 connectsthe central opening 90 with the annular passage 86 to thereby allowfluid enter the holes 88 to flow into the opening 98 and thence throughthe radial passageway 92 into the annular passageway 86.

Fluid located within the annular passageway 86 will traverse the coarsefilter 84 and the fine filter 82 in a radial direction and enter theholes 72 located on the pipe 78 for eventual discharge through the pipe70 to the external holding reservoir 42 ilustrated in FIG. ll.

In operation, fluid from the sump pump 36 is fed into the conicalportion 55 of the water purification system 38 to a point approximatelywhere the frusto-conical portion meets the lower portion 53 of the tank50.

Fluid from the grey water system will be under pressure caused by thesump pump 36. The grey water fluid fed into the manifold 60 underpressure of the pump 36 will impart a whirlpool action to the initialcharge of fluid located within the tank 50.

As a result of the whirlpool action, settleable foreign material havinga specific gravity greater than that of the fluid and located within thecharge of fluid will be thrown by centrifugal force to the periphery ofthe lower portion 53 of the tank 50. These heavier solids will fall as aresult of gravity along the conical surfaces 55 and will collect againstthe lowermost discharge orifice 56.

The combination of the manifold ring 60 and the pump 36 will inject astream of water under pressure into the tank 50 that is sufficient torotate the charge of fluid at approximately revolutions per minute.Investigation has shown that the substantially low rotational velocityof 20 revolutions per minute will remove approximately 50 percent of thesettleable solids from the fluid in the tank 50.

The tank cover 54 is hermetically sealed to the tank 50 and the pipe 70is open to the atmosphere. However, the path is a high impedance oneand, as a result, the water entering the ports 62 under pressure resultsin a pressure build up within the tank 50. Experimentation has shownthat a pressure sufficient to cause 20 to 30 revolutions per minute ofthe fluid located in the bottommost portion of the tank 50 generates avortex which has a higher level at the periphery of the tank than at thecenter of the center.

The rotating fluid will contain the foreign material having a specificgravity that is less than that of the fluid at the vortex. This foreignmaterial generally consists of oils, such as cooking oils, fats andother low specific gravity material. The rotating fluid will force thelow specific gravity material in concentrated amounts to the center ofthe vortex and against the hydrophobic material 74 which is located atthe uppermost portion of the tank 50.

Other solid contaminants either having a neutral buoyancy will generallyremain suspended and may or may not be transported through the filtersof the sys tem. In any event, this foreign material may be deemed benignand need not be of concern.

In review, therefore, we can see that, in operation, the low specificgravity material collects at the vortex and is brought into contact withthe hydrophobic material 74 as the level of the rotating fluid rises inthe tank 50. The higher specific gravity material is thrown bycentrifugal force to the periphery of the lower portion 53 of the tank50, where it eventually settles through the conical section 55 to thedischarge orifice 56.

The cleanest portion of the rotating fluid is, therefore, at thelowermost portion at the center where the openings 88 in the filterassembly 66 are located. The substantially clear fluid is then forcedinto the openings 88, the pressure differential being built up betweenthe tank 50 interior and atmosphere. This fluid will then flow throughthe passage 90 and into the radial passage 92 and into the annularpassage 86 for eventual filtering by the coarse filter 84 and the finefilter 82. The substantially filtered fluid will then enter the holes 72located in the pipe 70 for discharge into the treated water reservoir 42illustrated in FIG. 1.

In an effort to control bacteria growth, a cylinder 94 of a dry chlorineproducing compound may be located between the hydrophobic material 74and the upper baffle plate 76 as shown in FIG. 4. The actual shape ofthe chlorine compound and its placement is not critical and is dictatedby external requirements of the system. The use of the chlorine preventsalgae and other micro organisms from growing in the water medium. Thechlorine compound cylinder 94 is generally kept out of the water inorder to prevent rapid consumption of the chlorine. However, wheneverthe system is operated, the water level rises to immerse the cylinder 94which liberates adequate amounts of active chlorine compounds.

The size of the filters 82 and 84 and the hydrophobic element 74 and thechlorine compound cylinder 94 are designed and sized for the givenapplication and system so that the user must periodically remove andreplace the complete assembly illustrated in FIG. 4.

The separator and filter system illustrated in FIGS. 2, 3 and 4 willprovide a tertiary quality, treated water that should substantiallyreduce the demand for fresh water in any given dwelling. The water thenproduced without further treatment may be used and recirculated forwashing and irrigation purposes. If care is given to the foreignsubstances introduced into the grey water" during its utilization in thedwelling, and the user has not introduced any solutes which arepotentially harmful to life, the recovered water may even be used forlivestock and, if necessary, for drinking and cooking purposes.

In a completely automatic system, it is envisioned that a liquid levelsensor in the form of an overflow pipe may be used to control theinitial level of the charge of water filling the cylindrical tank 50.The overflow will simply be fed back to the sump pump 36 illustrated inFIG. 1. During continuous operation, a suitable solenoid valve may beused to interrupt the overflow during the application of pressure fromthe sump pump 36. However, the overflow may be needed in a quiescentoperation to prevent the tank from completely filling with water due toseepage or other means.

What is claimed as new is:

l. A separator comprising:

a sealed generally cylindrical holding tank having an upper portionextending along a generally central vertical axis and having an initialcharge of fluid therein and a lower portion integral with said upperportion and extending downwardly therefrom, and a generallyconically-shaped section terminating in a waste collection orificeintegral with said lower portion and extending downwardly therefrom;

means operatively engaging said tank in fluid communication with theinterior of said tank at approximately the intersection of said lowerportion with said conically-shaped section for introducing a fluidtherein under a pressure sufficient to impart a fluid vortex to theinitial charge of fluid within said tank about said central axissufficient to create a difference in the level of fluid within said tankbetween the center thereof and the periphery thereof in a manner raisingfluid into the upper portion of said tank;

a generally cylindrically housed filtering assembly located within saidtank and extending from said upper portion to said lower portion, saidfiltering assembly having filtered fluid removal means extending throughsaid filtering assembly from substantially said lower portion to saidupper portion and out of said tank and generally coaxially aligned withthe central vertical axis of said tank and in fluid communication withfluid in said tank for removing filtered fluid therefrom;

a generally cylindrical inner filter having a plurality of filteringpassages extending therethrough surrounding said filtered fluid removalmeans;

a generally cylindrical outer filter having a plurality of filteringpassages extending therethrough surrounding said inner filter and spacedfrom the internal wall of said filtering assembly, said inner filcludesa manifold surrounding said tank and having a plurality of inlet portsin fluid communication with the interior of said tank, said ports beinggenerally tangential with respect to said tank.

3. The separator of claim 1 wherein said filtered fluid v removal meansincludes an output pipe having a plurality of spaced apertures along theperiphery thereof.

4. The separator of claim 1 wherein the passages in said inner filterhave a particle size greater than approximately micron and the passagesin said outer filter have a particle size greater than approximately 5microns.

1. A separator comprising: a sealed generally cylindrical holding tankhaving an upper portion extending along a generally central verticalaxis and having an initial charge of fluid therein and a lower portionintegral with said upper portion and extending downwardly therefrom, anda generally conically-shaped section terminating in a waste collectionorifice integral with said lower portion and extending downwardlytherefrom; means operatively engaging said tank in fluid communicationwith the interior of said tank at approximately the intersection of saidlower portion with said conically-shaped section for introducing a fluidtherein under a pressure sufficient to impart a fluid vortex to theinitial charge of fluid within said tank about said central axissufficient to create a difference in the level of fluid within said tankbetween the center thereof and the periphery thereof in a manner raisingfluid into the upper portion of said tank; a generally cylindricallyhoused filtering assembly located within said tank and extending fromsaid upper portion to said lower portion, said filtering assembly havingfiltered fluid removal means extending through said filtering assemblyfrom substantially said lower portion to said upper portion and out ofsaid tank and generally coaxially aligned with the central vertical axisof said tank and in fluid communication with fluid in said tank forremoving filtered fluid therefrom; a generally cylindrical inner filterhaving a plurality of filtering passages extending therethroughsurrounding said filtered fluid removal means; a generally cylindricalouter filter having a plurality of filtering passages extendingtherethrough surrounding said inner filter and spaced from the internalwall of said filtering assembly, said inner filter having substantiallyfiner filtering passages than said passages in said outer filter;aperture means associated with said filtering assembly in fluidcommunication with both said means in fluid communication with theinterior of said tank and the space between said outer filter and theinner wall of said filtering assembly; and a generally cylindricalfilter of hydrophobic material associated with said filtering assemblysurrounding said filtered fluid removal means disposed above said innerand outer filters.
 2. The separator of claim 1 wherein said means influid communication with the interior of said tank includes a manifoldsurrounding said tank and having a plurality of inlet ports in fluidcommunication with the interior of said tank, said ports being generallytangential with respect to said tank.
 3. The separator of claim 1wherein said filtered fluid removal means includes an output pipe havinga plurality of spaced apertures along the periphery thereof.
 4. Theseparator of claim 1 wherein the passages in said inner filter have aparticle size greater than approximately 1/2 micron and the passages insaid outer filter have a particle size greater than approximately 5microns.